I'm getting ready to finish some quilts I've made for my young grandchildren. All have flannel backing (prewashed). Typically I trim my backing even with the quilt top when I bind it. Since I know these quilts will be washed a lot and as flannel frays so much, I am hesitant to only have one-quarter or three-eighths of an inch of flannel within the seam allowance on the back side where I'll be hand sewing the binding to the backing. I can just picture the flannel fraying back to the hand-stitching. I haven't trimmed the flannel off yet; is there something I can do with the excess to make the flannel edge sturdier?